If you’re a soon-to-be parent, you probably know that Amazon Baby Registry is a fantastic way to prepare for your little one’s arrival. It lets you curate a list of baby items you’ll need, and it even offers a Completion Discount, which is like a gift from the heavens for budget-conscious parents. But what if you’re having trouble using or redeeming this discount?  Don’t worry; I’ve been there, and I’m...